水王在哪

package demo;
import java.util.Stack;
public class Test {
    public static void main(String[]args)
    {

        String[] a ={"a","b","a","a","a","c","b"};
        String shuiwang=select(a);
        System.out.println("水王是"+shuiwang);;
    }

    static String select(String[] a)
    {
        Stack<String> s =new Stack<String>();
        s.push("#");

        for(int i=0;i<a.length;i++)
        {
            if(a[i].equals(s.peek())||s.peek().equals("#"))
            {
                s.push(a[i]);
            }
            else
            {
                s.pop();
            }
        }
        String rs=s.pop();
        return rs;
    }
}